Low-profile composite heat pipe

ABSTRACT

A low-profile composite heat pipe includes a flat plate-like first pipe component shaped like a flat plat member and having flow-guide grooves located at the inner surface between two opposite ends thereof and a wick structure sintered on the surface of the flow-guide grooves, a flat plate-like second pipe component having flow-guide grooves located at the inner surface between two opposite ends thereof and a wick structure sintered on the surface of the flow-guide grooves, an enclosed cavity defined in between the first pipe component and the second pipe component and surrounded by the wick structures of the first and second pipe components, and a working fluid contained in the enclosed cavity.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to heat pipe technology and more particularly, to a low-profile composite heat pipe that is formed of two flat pipe components and has low profile and uniform heat transfer characteristics.

2. Description of the Related Art

Various heat pipe designs have been disclosed for use in electronic products for quick transfer of waste heat. Following the market trend of the electronic industry toward a low profile design, the vertical installation space in an electronic device for heat pipe must be minimized. Thus, flat heat pipes are created. A conventional flat heat pipe may be made by making flow-guide grooves on the inside wall of a round pipe and then flatting the round pipe into a flat condition to reduce pipe height. Further, in order to comply with the arrangement of electronic components in an electronic product, or in order to comply with the demand for space arrangement in an electronic product, a heat pipe may be bent into a particular shape. However, bending a heat pipe into a particular shape can destruct the structure of the flow-guide grooves, lowering the heat transfer performance of the heat pipe. Further, employing an extrusion or roller ramming technique to make flow-guide grooves, the density of flow-guide grooves is limited, lowering the flow guide performance. Further, when flattening a curved heat pipe into a flat condition, if the wall is too thin or the flattening degree is too large, the flattening force can easily break the curved portion.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a low-profile composite heat pipe, which has a low profile, and intersected or parallel flow-guide grooves located on the inside to enhance flowing of the internal working fluid.

To achieve this and other objects of the present invention, a heat pipe comprises a flat plate-like first pipe component shaped like a flat plat member and having flow-guide grooves located at the inner surface between two opposite ends thereof and a wick structure sintered on the surface of the flow-guide grooves, a flat plate-like second pipe component having flow-guide grooves located at the inner surface between two opposite ends thereof and a wick structure sintered on the surface of the flow-guide grooves, an enclosed cavity defined in between the first pipe component and the second pipe component and surrounded by the wick structures of the first and second pipe components, and a working fluid contained in the enclosed cavity.

Further, the first pipe component comprises at least one first curved potion disposed between two opposite ends thereof; the second pipe component comprises at least one second curved portion disposed between two opposite ends thereof corresponding to the at least one first curved portion of the first pipe component.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a low-profile composite heat pipe in accordance with a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line A-A of FIG. 1.

FIG. 3 is an exploded view of the low-profile composite heat pipe in accordance with the first embodiment of the present invention before wick structure sintering.

FIG. 4 is an exploded view of the low-profile composite heat pipe in accordance with the first embodiment of the present invention after wick structure sintered.

FIG. 5 is a sectional view of a low-profile composite heat pipe in accordance with a second embodiment of the present invention.

FIG. 6 is a sectional view of a low-profile composite heat pipe in accordance with a third embodiment of the present invention.

FIG. 7 is a sectional view of a low-profile composite heat pipe in accordance with a fourth embodiment of the present invention.

FIG. 8 is an elevational view of a low-profile composite heat pipe in accordance with a fifth embodiment of the present invention.

FIG. 9 is an elevational view of a low-profile composite heat pipe in accordance with a sixth embodiment of the present invention.

FIG. 10 is an exploded view of a low-profile composite heat pipe in accordance with a seventh embodiment of the present invention before wick structure sintering.

FIG. 11 is a sectional view, in an enlarged scale, of Part A of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-4, a low-profile composite heat pipe 10 in accordance with a first embodiment of the present invention is shown comprising a first pipe component 1 and a second pipe component 2.

The first pipe component 1 is a narrow, elongated, curved, hollow flat member, defining a plurality of curved portions 11. Further, the first pipe component 1 comprises a base wall 12, a plurality of flow-guide grooves 4 longitudinally formed inside the base wall 12 in a parallel manner between the two opposite ends thereof by means of extrusion or roller ramming, and an endless upright wall 13 perpendicularly extended around the border of the base wall 12. The second pipe component 2 is a narrow, elongated, curved, hollow flat member configured subject to the configuration of the first pipe component 1, defining a plurality of curved portions 21 corresponding to the curved portions 11 of the first pipe component 1 and flow-guide grooves 4 at one side thereof. Further, a wick structure 5 is formed on an inner surface of the endless upright wall 13 of the first pipe component 1 and flow-guide grooves 4 of the first pipe component 1 and second pipe component 2 by sintering.

The second pipe component 2 is covered on the first pipe component 1 and sealed thereto by welding or ultrasonic fusion bonding, and thus an enclosed cavity 3 is defined in between the first pipe component 1 and the second pipe component 2. After formation of the heat pipe 10, the cavity 3 is kept in an airtight condition. Further, before closing the second pipe component 2 on the first pipe component 1, a working fluid 6 is filled in the space surrounded by the base wall 12 and endless upright wall 13 of the first pipe component 1. After filling of the working fluid 6 in the first pipe component 1, the second pipe component 2 is covered on the first pipe component 1 and sealed thereto air-tightly.

FIG. 5 illustrates a low-profile composite heat pipe in accordance with a second embodiment of the present invention. This second embodiment is substantially similar to the aforesaid first embodiment with the exception that the endless upright wall 13 of the first pipe component 1 defines an inner locating groove 131 in an inner surface thereof at a top side, and the second pipe component 2 is press-fitted into the inner locating groove 131 in flush with the topmost edge of the endless upright wall 13 of the first pipe component 1.

FIG. 6 illustrates a low-profile composite heat pipe in accordance with a third embodiment of the present invention. This third embodiment is substantially similar to the aforesaid first embodiment with the exception that the endless upright wall 13 defines an outer locating groove 132 in an outer surface thereof at a top side; the second pipe component 2 comprises a base wall 22, and an endless flange 23 perpendicularly downwardly extended around the border of the base wall 22 and press-fitted into the outer locating groove 132 in flush with the periphery of the endless upright wall 13 of the first pipe component 1.

FIG. 7 illustrates a low-profile composite heat pipe in accordance with a fourth embodiment of the present invention. This fourth embodiment is substantially similar to the aforesaid first embodiment with the exception that the endless upright wall 13 defines a top locating groove 133 at the topmost edge thereof; the second pipe component 2 comprises a base wall 22, and a protruding portion flange 24 protruded from the bottom surface thereof and fitted into the top locating groove 133 of the endless upright wall 13 of the first pipe component 1.

FIG. 8 illustrates a low-profile composite heat pipe in accordance with a fifth embodiment of the present invention. Unlike the curved portions 11 and 21 of the low-profile composite heat pipe 10 of the foresaid first embodiment that are disposed at the same plane, the curved portions 11 and 21 of the low-profile composite heat pipe 10 in accordance with this fifth embodiment are disposed at different elevations.

FIG. 9 illustrates a low-profile composite heat pipe in accordance with a sixth embodiment of the present invention. Unlike the low-profile composite heat pipe 10 of the foresaid first embodiment that has a uniform width, the first pipe component 1 and second pipe component 2 of the low-profile composite heat pipe 10 in accordance with this sixth embodiment are flat straight members gradually reducing in width from one end to the other end.

FIGS. 10 and 11 illustrate a low-profile composite heat pipe in accordance with a seventh embodiment of the present invention. This seventh embodiment is substantially similar to the aforesaid various embodiments with the exception that the flow-guide grooves 7 of the first pipe component 1 and second pipe component 2 in accordance with this seventh embodiment are intersected with one another.

In conclusion, the invention provides a low-profile composite heat pipe 10 that has the advantages and features as follows:

1. The low-profile composite heat pipe 10 is made by sealing a flat, elongated first pipe component 1 and a flat, elongated second pipe component 2 together, having a low profile characteristic.

2. The low-profile composite heat pipe 10 is made by sealing a flat, elongated first pipe component 1 and a flat, elongated second pipe component 2 together that are configured subject to the desired shape and processed by extrusion or roller ramming to provide flow-guide grooves 4 at the inner surface thereof. When the flat, elongated first pipe component 1 and the flat, elongated second pipe component 2 are bonded together, the flow-guide grooves 4 are kept intact for quick heat transfer. Further, by means of extrusion or roller ramming, a large amount of flow-guide grooves 4 can be densely made in the limited surface area of the flat, elongated first pipe component 1 and the flat, elongated second pipe component 2.

3. The low-profile composite heat pipe 10 is made by sealing a flat, elongated first pipe component 1 and a flat, elongated second pipe component 2 together. Thus, the desired flow-guide grooves 4 can be made at the flat, elongated first pipe component 1 and the flat, elongated second pipe component 2 before bonding, and can be kept intact after the flat, elongated second pipe component 2 are bonded together. 

What the invention claimed is:
 1. A low-profile composite heat pipe, comprising: a first pipe component shaped like a flat plat member, said first pipe component comprising a plurality of flow-guide grooves located at an inner surface between two opposite ends thereof; a second pipe component shaped like a flat plate member and covered on and bonded to said first pipe component; an enclosed cavity defined in between said first pipe component and said second pipe component in communication with the flow-guide grooves of said first pipe component.
 2. The low-profile composite heat pipe as claimed in claim 1, wherein said flow-guide grooves are made using one of extrusion and roller ramming techniques.
 3. The low-profile composite heat pipe as claimed in claim 1, wherein said flow-guide grooves are arranged in parallel.
 4. The low-profile composite heat pipe as claimed in claim 1, wherein said flow-guide grooves are intersected with one another.
 5. The low-profile composite heat pipe as claimed in claim 1, wherein said first pipe component further comprises a wick structure located at said flow-guide grooves.
 6. The low-profile composite heat pipe as claimed in claim 1, wherein said second pipe component further comprises a plurality of flow-guide grooves located between two opposite ends thereof in communication with said cavity, and a wick structured sintered on surfaces of said flow-guide grooves.
 7. The low-profile composite heat pipe as claimed in claim 1, wherein said first pipe component comprises at least one first curved potion disposed between two opposite ends thereof; said second pipe component comprises at least one second curved portion disposed between two opposite ends thereof corresponding to said at least one first curved portion of said first pipe component.
 8. The low-profile composite heat pipe as claimed in claim 1, wherein said first pipe component comprises a base wall, and an endless upright wall perpendicularly extended around the border of said base wall; said second pipe component is bonded to said endless upright wall of said first pipe component.
 9. The low-profile composite heat pipe as claimed in claim 1, wherein said first pipe component comprises a base wall, an endless upright wall perpendicularly extended around the border of said base wall, and an inner locating groove located on an inner surface of said endless upright wall at a top side; said second pipe component is press-fitted into said inner locating groove of said endless upright all of said first pipe component in a flush manner.
 10. The low-profile composite heat pipe as claimed in claim 1, wherein said first pipe component comprises a base wall, an endless upright wall perpendicularly extended around the border of the base wall thereof, and an outer locating groove located on an outer surface of said endless upright wall at a top side; said second pipe component comprises a base wall and an endless flange perpendicularly downwardly extended around the border of the base wall thereof and press-fitted into said outer locating groove of said endless upright wall of said first pipe component. 